Stained or discolored teeth are considered as a cosmetic impairment. Teeth's whitening is a cosmetic treatment done to improve the appearance of teeth. Teeth are whitened to remove impairments such as those resulting from the effects of coffee, cigarettes, and other substances that permanently stain or discolor teeth. Different techniques of teeth whitening or bleaching are known and relatively simple procedures improving the stained teeth appearance exist. The procedures can be conducted in a dental clinic, office or in a residential environment.
A variety of dental bleaching compositions and dental bleaching devices or trays exist on the market. Such dental bleaching compositions are typically applied to a person's teeth using a dental tray configured so as to retain the dental composition against the person's teeth. Treatment time can vary between about 10 minutes to a few hours and although conducted in a residential environment it can temporarily limit the user's freedom of speech, movement and function during the treatment period. In addition, it is uncomfortable for the user to keep a dental tray in the mouth over relatively long periods of time. User comfort during the teeth bleaching treatment duration may be improved by shortening the time of bleaching.
Most common bleaching agents used are peroxides, including but not limited to hydrogen peroxide, carbamide peroxide, sodium perborate, and sodium percarbonate. The simplest way to shorten the treatment time can be to increase the concentration of the peroxide. However, use of higher concentrations of bleaching agents (e.g., peroxides) can result in irritation and even some damage of oral mucosa such as gums or lips or other soft tissue.
As a result, the current methods of application of bleaching agents disclose using lower concentrations of bleaching agents, applying protection to the gums such as a protective light curable gingival protector or similar prior to application of the bleaching agent or using bleaching agents other than hydrogen peroxide such as chlorine dioxide and oxy-chlorine anions (U.S. Pat. No. 8,377,423).
Another way to accelerate bleaching time and speed up the chemical reaction related to the bleaching process can be concurrent application of heat or light or DC (Direct Current) electric current to the bleaching composition as disclosed in U.S. Pat. No. 7,775,795.